Ryckie G Wade, Justin CR Wormald, Andrea Figus

Carpal tunnel syndrome is a common problem and surgical decompression of the carpal tunnel is the most effective treatment. After surgical decompression, the palmar skin may be closed using either absorbable or non-absorbable sutures. To date, there is conflicting evidence regarding the ideal suture material and this formed the rationale for our review. To assess the effects of absorbable versus non-absorbable sutures for skin closure after elective carpal tunnel decompression surgery in adults on postoperative pain, hand function, scar satisfaction, wound inflammation and adverse events. We searched the following databases on 30 October 2017: the Cochrane Neuromuscular Specialised Register, CENTRAL, MEDLINE, and Embase. We searched two clinical trials registries on 30 October 2017. We considered all randomised or quasi-randomised controlled trials comparing absorbable and non-absorbable sutures for skin closure after any form of carpal tunnel decompression surgery in adults. The unit of analysis was the hand rather than the patient. We performed meta-analysis of direct comparisons to generate standardised mean differences (SMDs) with 95% confidence intervals (CIs) in pain scores and risk ratios (RRs) with 95% CIs for dichotomous outcomes, such as wound inflammation. The primary outcome was postoperative pain. Secondary outcomes included hand function, scar satisfaction, scar inflammation and adverse events (complications). We assessed the quality of evidence for key outcomes using GRADE. We included five randomised trials (255 participants). The trials were all European (UK, Republic of Ireland, Denmark and the Netherlands). Where quoted, the mean age of participants was between 48 and 53 years. The trials measured outcomes between one and 12 weeks postoperatively.Meta-analysis of postoperative pain scores for absorbable versus non-absorbable sutures at 10 days following open carpal tunnel decompression (OCTD) produced a SMD of 0.03 (95% CI -0.43 to 0.48; 3 studies, number of participants (N) = 137; I2 = 43%); the SMD suggests little or no difference, but with a high degree of uncertainty because of very low-quality evidence. At 10 days following endoscopic carpal tunnel decompression (ECTD), the SMD for postoperative pain with use of absorbable versus non-absorbable sutures was -0.81 (95% CI -1.36 to -0.25; 1 study; N = 54); although the SMD is consistent with a large effect, the very low-quality evidence means the results are very uncertain. Only the OCTD studies provided pain data at 6 weeks, when the SMD was 0.06 (95% CI -0.72 to 0.84; 4 studies; N = 175; I2 = 84%), which indicates little or no evidence of difference, but with a high degree of uncertainty (very low-quality evidence). The RR for wound inflammation using absorbable versus non-absorbable sutures after OCTD was 2.28 (95% CI 0.24 to 21.91; N = 95; I2 = 90%) and after ECTD 0.93 (95% CI 0.06 to 14.09; 1 study, N = 54). Any difference in effect on wound inflammation is uncertain because the quality of evidence is very low. One study reported postoperative hand function but found no evidence of a difference between suture types at two weeks (mean difference (MD) -0.10, 95% CI -0.53 to 0.33, N = 36), with similar findings at six and 12 weeks. Only the ECTD trial reported scar satisfaction, with 25 out of 28 people reporting a 'nice' result in the absorbable-suture group, versus 18 out of 26 in the group who received non-absorbable sutures (RR 1.29, 95% CI 0.97 to 1.72, N = 54). These findings are also very uncertain as we judged the quality of the evidence to be very low. All studies were at high risk of bias for most domains. No trials reported adverse events. It is uncertain whether absorbable sutures confer better, worse or equivalent outcomes compared to non-absorbable sutures following carpal tunnel decompression, because the quality of evidence is very low. Use of absorbable suture eliminates the need for suture removal, which could confer considerable savings to patients and healthcare providers alike. We need rigorously-performed, non-inferiority randomised trials with economic analyses to inform choice of suture.